By electrophoresis and isoelectric focusing, we have demonstrated that asialotranscortin consists of perhaps a dozen different proteins having varying affinity for cortisol. This work, performed on out-dated pooled plasma, leaves unanswered such questions as artifact formation and individual variation. Consequently, we propose to repeat this work on a large volume of plasma, carefully collected and preserved, from a single individual. The most abundant fractions will be used for antibody production. All fractions will be tested for binding of cortisol and progresterone, amino acid and carbohydrate composition, peptide mapping and immunological relatedness.